What are the total closing costs? What is your total escrow shortage? (I'm guessing about $250*12 or $3k?) I saw your last thread and thought it was confusing because you are treating the escrow shortage as part of your house payment. It's better to think of it as an additional tax amount that you owe, whether you spread it out over the next year, or roll it into a new loan. Or pay it all off right now, for that matter.
I think you should find out what you need to do with your current lender to drop PMI and work toward that, rather than your proposed triple whammy:
1. Incurring closing costs on a new loan (whether or not they are rolled into the loan or paid up front)
2. Increasing your interest rate for the next 20 years
3. Rolling a short-term liability (property tax shortage in escrow) into your loan.
My short answer is "No, you shouldn't refinance to get rid of PMI" based on the above.